mirror of
https://github.com/catseye/SixtyPical.git
synced 2024-11-28 12:51:10 +00:00
72 lines
2.9 KiB
Markdown
72 lines
2.9 KiB
Markdown
SixtyPical
|
|
==========
|
|
|
|
_Version 0.17. Work-in-progress, everything is subject to change._
|
|
|
|
**SixtyPical** is a 6502-like programming language with advanced
|
|
static analysis.
|
|
|
|
"6502-like" means that it has similar restrictions as programming
|
|
in 6502 assembly (e.g. the programmer must choose the registers that
|
|
values will be stored in) and is concomitantly easy for a compiler to
|
|
translate it to 6502 machine language code.
|
|
|
|
"Advanced static analysis" includes _abstract interpretation_, where we
|
|
go through the program step by step, tracking not just the changes that
|
|
happen during a _specific_ execution of the program, but _sets_ of changes
|
|
that could _possibly_ happen in any run of the program. This lets us
|
|
determine that certain things can never happen, which we can then formulate
|
|
as safety checks.
|
|
|
|
In practice, this means it catches things like
|
|
|
|
* you forgot to clear carry before adding something to the accumulator
|
|
* a subroutine that you call trashes a register you thought was preserved
|
|
* you tried to read or write a byte beyond the end of a byte array
|
|
* you tried to write the address of something that was not a routine, to
|
|
a jump vector
|
|
|
|
and suchlike. It also provides some convenient operations based on
|
|
machine-language programming idioms, such as
|
|
|
|
* copying values from one register to another (via a third register when
|
|
there are no underlying instructions that directly support it); this
|
|
includes 16-bit values, which are copied in two steps
|
|
* explicit tail calls
|
|
* indirect subroutine calls
|
|
|
|
The reference implementation can analyze and compile SixtyPical programs to
|
|
6502 machine code.
|
|
|
|
Quick Start
|
|
-----------
|
|
|
|
If you have the [VICE][] emulator installed, from this directory, you can run
|
|
|
|
./loadngo.sh c64 eg/c64/hearts.60p
|
|
|
|
and it will compile the [hearts.60p source code](eg/c64/hearts.60p) and
|
|
automatically start it in the `x64` emulator, and you should see:
|
|
|
|
|
|
|
|
You can try the `loadngo.sh` script on other sources in the `eg` directory
|
|
tree, which contains more extensive examples, including an entire
|
|
game(-like program); see [eg/README.md](eg/README.md) for a listing.
|
|
|
|
[VICE]: http://vice-emu.sourceforge.net/
|
|
|
|
Documentation
|
|
-------------
|
|
|
|
* [Design Goals](doc/Design%20Goals.md)
|
|
* [SixtyPical specification](doc/SixtyPical.md)
|
|
* [SixtyPical revision history](HISTORY.md)
|
|
* [Literate test suite for SixtyPical syntax](tests/SixtyPical%20Syntax.md)
|
|
* [Literate test suite for SixtyPical analysis](tests/SixtyPical%20Analysis.md)
|
|
* [Literate test suite for SixtyPical compilation](tests/SixtyPical%20Compilation.md)
|
|
* [Literate test suite for SixtyPical fallthru optimization](tests/SixtyPical%20Fallthru.md)
|
|
* [6502 Opcodes used/not used in SixtyPical](doc/6502%20Opcodes.md)
|
|
* [Output formats supported by `sixtypical`](doc/Output%20Formats.md)
|
|
* [TODO](TODO.md)
|